OLA

Case Study: TC-4 (Ti-6Al-4V) Hip Joint & Custom Bone Plate Set

Medical-Grade TC-4 Titanium | SLM | FDA / CE / NMPA Compliant Orthopedic Implant Set

Orthopedic Implant Case Study

1. Background

An orthopedic specialty hospital was consolidating its hip arthroplasty and complex-trauma fracture-fixation workflows onto a single implant platform made from one biocompatible alloy: TC-4 (Ti-6Al-4V). The legacy workflow mixed three different material systems — cast Co-Cr-Mo for the femoral stem, plasma-sprayed Ti for the acetabular cup, and stock Ti-6Al-4V plates for fracture fixation — which complicated post-op imaging, required separate sterilization cycles, and forced the surgical team to manage three different supplier chains. A unified TC-4 implant set (porous acetabular cup, femoral stem, ceramic femoral head, and patient-specific anatomical bone plate) was needed to simplify the supply chain, streamline the OR, and enable consistent post-op imaging and revision.

2. The Challenge

Design requirements included:

· Single-alloy platform: TC-4 (Ti-6Al-4V) for cup, stem, and plate — no Co-Cr-Mo, no mixed alloys

· Porous acetabular cup with integrated bone-ingrowth lattice and screw-fixation holes

· Femoral stem with rough proximal surface for cementless osseointegration

· Ceramic femoral head (BIOLOX delta) for low-wear bearing couple

· Patient-specific anatomical bone plate, designed from the patient's CT data, with multiple screw holes

· ASTM F136 / ISO 5832-3 / GB/T 13810 material certification for all TC-4 components

· Biocompatibility per ISO 10993-1 (cytotoxicity, sensitization, irritation, systemic toxicity)

· Class III medical device, FDA 510(k), CE MDR, NMPA documentation all ready

· Single-piece monolithic TC-4 construction — no welded anti-migration features, no adhesive

· 8-week lead time from CT data to sterile-packed, certified implant set

3. The Solution

The implant set was redesigned as four matched TC-4 (Ti-6Al-4V) components manufactured by Selective Laser Melting (SLM) in medical-grade Ti-6Al-4V ELI powder (ASTM F136, ISO 5832-3, GB/T 13810). The acetabular cup was printed as a single monolithic TC-4 part with an integrated porous outer lattice (600-800 μm cell size, 70% porosity — the validated range for osteoblast attachment) and two screw-fixation holes. The femoral stem was printed with a rough as-built proximal surface for cementless osseointegration and a polished distal surface for fatigue performance. The custom anatomical bone plate was designed directly from the patient's CT data, with pre-contoured curvature matching the bone surface, and screw holes pre-positioned to avoid critical anatomical structures (nerves, vessels, growth plates).

After printing, every TC-4 component was hot isostatic pressed (HIP) for 100% density, passivated per ASTM F86 for biocompatibility, the bearing surfaces were finish-machined and polished to Ra < 0.05 μm, and the ceramic femoral head was fitted. The complete set was cleaned, gamma-sterilized, and serial-numbered with full material traceability back to the powder lot per ASTM F2979. Because all metal components are TC-4, the set produces consistent post-op CT/MRI imaging (no Co-Cr-Mo streak artifacts) and can be processed through a single sterilization cycle.

 

Figure 1: TC-4 (Ti-6Al-4V) medical implant set — SLM-printed porous acetabular cup with screw holes, ceramic femoral head, and custom anatomical bone plate (front view, all components in one set)

 

Figure 2: Same set from a different angle — femoral stem with rough proximal surface for cementless fixation, custom anatomical plate with multiple screw holes, and porous acetabular cup

4. The Result

· Single-alloy TC-4 platform — cup, stem, plate all in Ti-6Al-4V — consistent post-op imaging, single sterilization cycle

· Patient-specific bone plate — designed from CT data, pre-contoured, screws pre-positioned to avoid critical anatomy

· 100% density TC-4 core — HIP + CT scan verified, no porosity in load-bearing region

· ASTM F136 / ISO 5832-3 / GB/T 13810 — full material certification, ASTM F2979 traceability

· ISO 10993 biocompatibility — cytotoxicity, sensitization, irritation, systemic toxicity — all pass

· Multi-region regulatory — FDA 510(k), CE MDR, NMPA documentation all prepared

· Faster OR turnover — one supplier, one sterilization cycle, one implant set per case

· Lead time: 8 weeks — from CT data to sterile-packed, certified implant set

“We replaced three material systems and three supplier chains with one TC-4 platform. The OR team gets a single implant set per case, post-op imaging is clean, and the patient-specific plate matches the bone surface exactly.”

 

Material: TC-4 (Ti-6Al-4V) per GB/T 13810, ASTM F136 / ISO 5832-3 ELI  |  Process: SLM + HIP + Passivation  |  Application: Hip Joint + Anatomical Bone Plate Set